In drilling and completion of subterranean wells, such as oil and gas wells, it is often desirable to place or form a seal within the well bore or well bore casing.
For certain drilling or completion tasks, it is further desirable to subsequently remove the seal. Removable sealing tools such as packers and bridge plugs are known for these general purposes. However, retrieving a removable packer or bridge plug is often a complex, expensive, and time consuming process.
It is frequently simpler and less expensive to remove a packer or bridge plug by milling or drilling them from the well bore or casing. However, the milling or drilling operations may be slowed because of the materials of the packer or bridge plug employed. For example, these downhole tools are frequently formed including metallic components, such as hardened iron or steel, which are difficult, or require specialized tools and techniques, to mill or drill.
Additionally, some known packers and bridge plugs are formed from specialized and costly materials to achieve the result of an effective seal that is relatively easy to drill, but with the disadvantage that such packers and bridge plugs remain expensive owing to the cost of the materials employed.
Further, setting methods for known packers and bridge plugs often require a significant force or impulse, such as an explosive charge, to set the packer or bridge plug within a well casing. Because of forces expended during such setting processes, such packers or bridge plugs are rendered unsuitable for use within a PVC casing since the a PVC casing may be ruptured by such a setting force.
Accordingly, a bridge plug and a setting tool for setting a drillable plug in a well bore or casing is desirable. Further, it is desirable for such a bridge plug and setting tool to be useable in PVC as well as other types of casings.